Bricks exhibiting negative Poisson's ratio

Abstract

A brick includes outer walls defining a hollow interior space, the outer walls including: substantially flat top and bottom walls; and side walls angled inwards toward a central portion of the NPR brick, such that application of a compressive force between the top and bottom walls causes a lateral dimension of the brick between opposite side walls to decrease. At least some of the outer walls of the brick include a material having a negative Poisson's ratio (NPR).

What is claimed is: 
     
       1. A brick comprising:
 outer walls defining a hollow interior space, the outer walls comprising:
 substantially flat top and bottom walls; and 
 side walls angled inwards toward a central portion of the brick, such that application of a compressive force between the top and bottom walls causes a lateral dimension of the brick between opposite side walls to decrease, 
 
 in which at least some of the outer walls of the brick include a material having a negative Poisson's ratio (NPR). 
 
     
     
       2. The brick of  claim 1 , in which the at least some of the outer walls of the brick include an NPR foam material. 
     
     
       3. The brick of  claim 2 , in which the outer walls of the brick include an NPR ceramic foam. 
     
     
       4. The brick of  claim 2 , in which the outer walls of the brick include an NPR polymer foam. 
     
     
       5. The brick of  claim 2 , in which the NPR foam material comprises an isotropic NPR foam material. 
     
     
       6. The brick of  claim 2 , in which at least some of the side walls each defines a corner that points toward the central portion of the brick. 
     
     
       7. The brick of  claim 2 , in which at least some of the side walls each defines a concave profile. 
     
     
       8. The brick of  claim 2 , in which the top, bottom, and side walls of the brick define a hollow interior space at the central portion of the brick. 
     
     
       9. A brick wall comprising:
 an NPR brick configured to exhibit NPR behavior, the NPR brick comprising:
 substantially flat top and bottom walls; and 
 four side walls, each side wall defining a first angled region angled inwards toward a central portion of the NPR brick; 
 
 a positive Poisson's ratio (PPR) brick disposed adjacent to the NPR brick, the PPR brick comprising:
 substantially flat top and bottom walls; and 
 four side walls, each side wall defining a second angled region angled outwards away from a central portion of the PPR brick, 
 
 wherein the second angled region of one of the side walls of the PPR brick is nested within the first angled region of one of the side walls of the NPR brick; and 
 
       mortar disposed between the NPR brick and the PPR brick. 
     
     
       10. The brick wall of  claim 9 , in which the top, bottom, and side walls of the NPR brick define a hollow interior space at the central portion of the NPR brick. 
     
     
       11. The brick wall of  claim 9 , in which the top, bottom, and side walls of the PPR brick define a hollow interior space at the central portion of the PPR brick. 
     
     
       12. The brick wall of  claim 9 , in which at least some of the side walls of the NPR brick each defines a corner that points toward the central portion of the NPR brick. 
     
     
       13. The brick of  claim 9 , in which at least some of the side walls of the NPR brick each defines a concave profile. 
     
     
       14. The brick wall of  claim 9 , in which at least some of the side walls of the PPR brick each defines a corner that points away from the central portion of the NPR brick. 
     
     
       15. The brick of  claim 9 , in which at least some of the side walls of the PPR brick each defines a convex profile. 
     
     
       16. The brick wall of  claim 9 , in which the NPR brick comprises an NPR foam material having a Poisson's ratio of less than 0. 
     
     
       17. The brick wall of  claim 9 , in which the NPR foam material comprises an NPR ceramic foam. 
     
     
       18. The brick wall of  claim 9 , in which the NPR foam material comprises an NPR polymer foam. 
     
     
       19. The brick of  claim 9 , in which the NPR foam material comprises an isotropic NPR foam material. 
     
     
       20. The brick wall of  claim 9 , in which the NPR foam material is composed of a cellular structure having a characteristic dimension of between 0.1 μm and 3 mm. 
     
     
       21. The brick wall of  claim 9 , in which the NPR foam material comprises reentrant structures. 
     
     
       22. The brick wall of  claim 9 , in which the NPR brick comprises a composite material comprising the NPR foam material and a positive Poisson's ratio (PPR) material. 
     
     
       23. The brick wall of  claim 9 , in which the mortar comprises an NPR foam material. 
     
     
       24. A method of making a brick wall, the method comprising:
 laying an NPR brick and a PPR brick adjacent to one another to form a portion of a row of the brick wall, 
 in which the NPR brick comprises:
 substantially flat top and bottom walls; and 
 four side walls, each side wall defining a first angled region angled inwards toward a central portion of the NPR brick, 
 
 in which the PPR brick comprises:
 substantially flat top and bottom walls; and 
 four side walls, each side wall defining a second angled region angled outwards away from a central portion of the PPR brick, and 
 
 in which laying the NPR brick and the PPR brick comprises:
 nesting the second angled region of one of the side walls of the PPR brick within the first angled region of one of the side walls of the NPR brick, and 
 disposing mortar between the NPR brick and the PPR brick.